NO. 5 CAMBRIAN TRILOBITES 337 



rings in the axial lobe that are well defined by narrow furrows on the 

 pleural lobes. Surface unknown. 



There appears to be a gradation in size among the cranidia from 

 9 mm. up to 24 mm. in length, and the associated pygidia from 3 mm. 

 to 23 mm. in length. 



It is possible that a second species is represented in the larger speci- 

 mens, but with the material now in hand this is too uncertain to base 

 a species on. 



No traces of the test or outer surface have been found. 



At locality ga this species is associated with : 



Lingulella desiderata (Walcott) 

 Lingulella similis (Walcott) 

 Ptychoparia sp. undt. 



At locality 1 1 it is associated with : 



Lingulella ino (Walcott) 

 Lingulella tar pa (Walcott) 



And at locality 14a with : 



Micromitra alabamaensis (Walcott) 



Obolus willisi (Walcott) 



Obolus {Westonia) ella (Hall and Whitfield) 



Lingulella similis (Walcott) 



IVimanella saffordi (Walcott) 



Ptychoparia sp. undt. 



Formation and locality. — Middle Cambrian : Rome formation : 

 (9) Shaly sandstone on southeastern slope of ridge i mile (1.6 km.) 

 north of the northwest corner of Harlan Knob, about 4 miles (6.4 

 km.) northeast of Rogersville ; and (ga) on the south shore of the 

 Holston River at Melinda Ferry, 5 miles (8 km.) southwest of 

 Rogersville, both in Hawkins County ; (11) sandstones and shales 

 of the Rome formation, about i mile (1.6 km.) east of. Post Oak 

 Springs, Roane County; (iib) in ridge, at Woods Creek Gap, 6 

 miles (9.6 km.) northeast of Knoxville; also (12b) southeast end 

 of McAnnallys Ridge, 12 miles (19.3 km.) northeast of Knoxville; 

 and (14a) along First Gap Creek, 4 miles (6.4 km.) north-northeast 

 of Knoxville, all three in Knox County, and all in Tennessee. 



BATHYURISCUS BATIS, new species 



Plate 48, figs. 4, 4a 



This fine species has 8 thoracic segments, a strong glabella, and a 

 large pygidium. It occurs in a hard siliceous rock in which the 



